/*
 *  video.c - ACPI Video Driver ($Revision:$)
 *
 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
 *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>

#include <asm/uaccess.h>

#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#define ACPI_VIDEO_COMPONENT		0x08000000
#define ACPI_VIDEO_CLASS		"video"
#define ACPI_VIDEO_DRIVER_NAME		"ACPI Video Driver"
#define ACPI_VIDEO_BUS_NAME		"Video Bus"
#define ACPI_VIDEO_DEVICE_NAME		"Video Device"
#define ACPI_VIDEO_NOTIFY_SWITCH	0x80
#define ACPI_VIDEO_NOTIFY_PROBE		0x81
#define ACPI_VIDEO_NOTIFY_CYCLE		0x82
#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT	0x83
#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT	0x84

#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS	0x82
#define	ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS	0x83
#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS	0x84
#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS	0x85
#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF		0x86


#define ACPI_VIDEO_HEAD_INVALID		(~0u - 1)
#define ACPI_VIDEO_HEAD_END		(~0u)


#define _COMPONENT		ACPI_VIDEO_COMPONENT
ACPI_MODULE_NAME		("acpi_video")

MODULE_AUTHOR("Bruno Ducrot");
MODULE_DESCRIPTION(ACPI_VIDEO_DRIVER_NAME);
MODULE_LICENSE("GPL");

static int acpi_video_bus_add (struct acpi_device *device);
static int acpi_video_bus_remove (struct acpi_device *device, int type);
static int acpi_video_bus_match (struct acpi_device *device, struct acpi_driver *driver);

static struct acpi_driver acpi_video_bus = {
	.name = ACPI_VIDEO_DRIVER_NAME,
	.class = ACPI_VIDEO_CLASS,
	.ops = {
		.add = acpi_video_bus_add,
		.remove = acpi_video_bus_remove,
		.match = acpi_video_bus_match,
	},
};

struct acpi_video_bus_flags {
	u8	multihead:1;	/* can switch video heads */
	u8	rom:1;		/* can retrieve a video rom */
	u8	post:1;		/* can configure the head to */
	u8	reserved:5;
};

struct acpi_video_bus_cap {
	u8	_DOS:1; /*Enable/Disable output switching*/
	u8	_DOD:1; /*Enumerate all devices attached to display adapter*/
	u8	_ROM:1; /*Get ROM Data*/
	u8	_GPD:1; /*Get POST Device*/
	u8	_SPD:1; /*Set POST Device*/
	u8	_VPO:1; /*Video POST Options*/
	u8	reserved:2;
};

struct acpi_video_device_attrib{
	u32	display_index:4; /* A zero-based instance of the Display*/
	u32	display_port_attachment:4; /*This field differenates displays type*/
	u32	display_type:4;	/*Describe the specific type in use*/
	u32	vendor_specific:4; /*Chipset Vendor Specifi*/ 
	u32	bios_can_detect:1; /*BIOS can detect the device*/
	u32	depend_on_vga:1; /*Non-VGA output device whose power is related to 
				   the VGA device.*/
	u32	pipe_id:3; /*For VGA multiple-head devices.*/
	u32	reserved:10; /*Must be 0*/
	u32	device_id_scheme:1; /*Device ID Scheme*/
};

struct acpi_video_enumerated_device {
	union {
		u32 int_val;
		struct acpi_video_device_attrib	attrib;
	} value;
	struct acpi_video_device *bind_info;
};

struct acpi_video_bus {
	acpi_handle	handle;
	u8	dos_setting;
	struct acpi_video_enumerated_device *attached_array;
	u8			attached_count;
	struct acpi_video_bus_cap	cap;
	struct acpi_video_bus_flags flags;
	struct semaphore	sem;
	struct list_head	video_device_list;
	struct proc_dir_entry 	*dir;
};

struct acpi_video_device_flags {
	u8	crt:1;
	u8	lcd:1;
	u8	tvout:1;
	u8	bios:1;
	u8	unknown:1;
	u8	reserved:3;
};

struct acpi_video_device_cap {
	u8	_ADR:1;	/*Return the unique ID */
	u8	_BCL:1; /*Query list of brightness control levels supported*/
	u8	_BCM:1; /*Set the brightness level*/
	u8	_DDC:1; /*Return the EDID for this device*/
	u8	_DCS:1; /*Return status of output device*/
	u8	_DGS:1; /*Query graphics state*/
	u8	_DSS:1; /*Device state set*/
	u8	_reserved:1;
};

struct acpi_video_device_brightness {
	int	curr;
	int	count;
	int	*levels;
};

struct acpi_video_device {
	acpi_handle		handle;
	unsigned long		device_id;
	struct acpi_video_device_flags	flags;
	struct acpi_video_device_cap	cap;
	struct list_head	entry;
	struct acpi_video_bus	*video;
	struct acpi_device	*dev;
	struct acpi_video_device_brightness *brightness;
};


/* bus */
static int acpi_video_bus_info_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_bus_info_fops = {
	.open		= acpi_video_bus_info_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int acpi_video_bus_ROM_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_bus_ROM_fops = {
	.open		= acpi_video_bus_ROM_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int acpi_video_bus_POST_info_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_bus_POST_info_fops = {
	.open		= acpi_video_bus_POST_info_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int acpi_video_bus_POST_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_bus_POST_fops = {
	.open		= acpi_video_bus_POST_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};


static int acpi_video_bus_DOS_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_bus_DOS_fops = {
	.open		= acpi_video_bus_DOS_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

/* device */
static int acpi_video_device_info_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_device_info_fops = {
	.open		= acpi_video_device_info_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int acpi_video_device_state_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_device_state_fops = {
	.open		= acpi_video_device_state_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int acpi_video_device_brightness_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_device_brightness_fops = {
	.open		= acpi_video_device_brightness_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int acpi_video_device_EDID_open_fs(struct inode *inode, struct file *file);
static struct file_operations acpi_video_device_EDID_fops = {
	.open		= acpi_video_device_EDID_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static char	device_decode[][30] = {
	"motherboard VGA device",
	"PCI VGA device",
	"AGP VGA device",
	"UNKNOWN",
};

static void acpi_video_device_notify ( acpi_handle handle, u32 event, void *data);
static void acpi_video_device_rebind( struct acpi_video_bus *video);
static void acpi_video_device_bind( struct acpi_video_bus *video, struct acpi_video_device *device);
static int acpi_video_device_enumerate(struct acpi_video_bus *video);
static int acpi_video_switch_output( struct acpi_video_bus *video, int	event);
static int acpi_video_get_next_level( struct acpi_video_device *device, u32 level_current,u32 event);
static void acpi_video_switch_brightness ( struct acpi_video_device *device, int event);


/* --------------------------------------------------------------------------
                               Video Management
   -------------------------------------------------------------------------- */

/* device */

static int
acpi_video_device_query (
	struct acpi_video_device	*device,
	unsigned long			*state)
{
	int			status;
	ACPI_FUNCTION_TRACE("acpi_video_device_query");
	status = acpi_evaluate_integer(device->handle, "_DGS", NULL, state);

	return_VALUE(status);
}

static int
acpi_video_device_get_state (
	struct acpi_video_device	*device,
	unsigned long 		*state)
{
	int			status;

	ACPI_FUNCTION_TRACE("acpi_video_device_get_state");

	status = acpi_evaluate_integer(device->handle, "_DCS", NULL, state);

	return_VALUE(status);
}

static int
acpi_video_device_set_state (
	struct acpi_video_device	*device,
	int			state)
{
	int			status;
	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
	struct acpi_object_list	args = {1, &arg0};

	ACPI_FUNCTION_TRACE("acpi_video_device_set_state");

	arg0.integer.value = state;
	status = acpi_evaluate_integer(device->handle, "_DSS", &args, NULL);

	return_VALUE(status);
}

static int
acpi_video_device_lcd_query_levels (
	struct acpi_video_device	*device,
	union acpi_object		**levels)
{
	int			status;
	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object	*obj;


	ACPI_FUNCTION_TRACE("acpi_video_device_lcd_query_levels");

	*levels = NULL;

	status = acpi_evaluate_object(device->handle, "_BCL", NULL, &buffer);
	if (!ACPI_SUCCESS(status))
		return_VALUE(status);
	obj = (union acpi_object *) buffer.pointer;
	if (!obj && (obj->type != ACPI_TYPE_PACKAGE)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _BCL data\n"));
		status = -EFAULT;
		goto err;
	}

	*levels = obj;

	return_VALUE(0);

err:
	if (buffer.pointer)
		kfree(buffer.pointer);

	return_VALUE(status);
}

static int
acpi_video_device_lcd_set_level (
	struct acpi_video_device	*device,
	int				level)
{
	int			status;
	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
	struct acpi_object_list	args = {1, &arg0};

	ACPI_FUNCTION_TRACE("acpi_video_device_lcd_set_level");

	arg0.integer.value = level;
	status = acpi_evaluate_object(device->handle, "_BCM", &args, NULL);

	printk(KERN_DEBUG "set_level status: %x\n", status);
	return_VALUE(status);
}

static int
acpi_video_device_lcd_get_level_current (
	struct acpi_video_device	*device,
	unsigned long 	*level)
{
	int			status;
	ACPI_FUNCTION_TRACE("acpi_video_device_lcd_get_level_current");

	status = acpi_evaluate_integer(device->handle, "_BQC", NULL, level);

	return_VALUE(status);
}

static int
acpi_video_device_EDID (
	struct acpi_video_device	*device,
	union acpi_object		**edid,
	ssize_t				length)
{
	int			status;
	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object	*obj;
	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
	struct acpi_object_list	args = {1, &arg0};

	ACPI_FUNCTION_TRACE("acpi_video_device_get_EDID");

	*edid = NULL;

	if (!device)
		return_VALUE(-ENODEV);
	if (length == 128)
		arg0.integer.value = 1;
	else if (length == 256)
		arg0.integer.value = 2;
	else
		return_VALUE(-EINVAL);

	status = acpi_evaluate_object(device->handle, "_DDC", &args, &buffer);
	if (ACPI_FAILURE(status))
		return_VALUE(-ENODEV);

	obj = (union acpi_object *) buffer.pointer;

	if (obj && obj->type == ACPI_TYPE_BUFFER)
		*edid = obj;
	else {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _DDC data\n"));
		status = -EFAULT;
		kfree(obj);
	}

	return_VALUE(status);
}


/* bus */

static int
acpi_video_bus_set_POST (
	struct acpi_video_bus	*video,
	unsigned long		option)
{
	int			status;
	unsigned long		tmp;
	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
	struct acpi_object_list	args = {1, &arg0};

	ACPI_FUNCTION_TRACE("acpi_video_bus_set_POST");

	arg0.integer.value = option;

	status = acpi_evaluate_integer(video->handle, "_SPD", &args, &tmp);
	if (ACPI_SUCCESS(status))
		status = tmp ? (-EINVAL):(AE_OK);

	return_VALUE(status);
}

static int
acpi_video_bus_get_POST (
	struct acpi_video_bus	*video,
	unsigned long		*id)
{
	int status;

	ACPI_FUNCTION_TRACE("acpi_video_bus_get_POST");

	status = acpi_evaluate_integer(video->handle, "_GPD", NULL, id);

	return_VALUE(status);
}

static int
acpi_video_bus_POST_options (
	struct acpi_video_bus	*video,
	unsigned long		*options)
{
	int			status;
	ACPI_FUNCTION_TRACE("acpi_video_bus_POST_options");

	status = acpi_evaluate_integer(video->handle, "_VPO", NULL, options);
	*options &= 3;

	return_VALUE(status);
}

/*
 *  Arg:
 *  	video		: video bus device pointer
 *	bios_flag	: 
 *		0.	The system BIOS should NOT automatically switch(toggle)
 *			the active display output.
 *		1.	The system BIOS should automatically switch (toggle) the
 *			active display output. No swich event.
 *		2.	The _DGS value should be locked.
 *		3.	The system BIOS should not automatically switch (toggle) the
 *			active display output, but instead generate the display switch
 *			event notify code.
 *	lcd_flag	:
 *		0.	The system BIOS should automatically control the brightness level
 *			of the LCD, when the power changes from AC to DC
 *		1. 	The system BIOS should NOT automatically control the brightness 
 *			level of the LCD, when the power changes from AC to DC.
 * Return Value:
 * 		-1	wrong arg.
 */

static int
acpi_video_bus_DOS(
	struct acpi_video_bus	*video,
	int			bios_flag,
	int			lcd_flag)
{
	acpi_integer		status = 0;
	union acpi_object	arg0 = {ACPI_TYPE_INTEGER};
	struct acpi_object_list	args = {1, &arg0};

	ACPI_FUNCTION_TRACE("acpi_video_bus_DOS");

	if (bios_flag < 0 || bios_flag >3 || lcd_flag < 0 || lcd_flag > 1){
		status = -1;
		goto Failed;
	}
	arg0.integer.value = (lcd_flag << 2) | bios_flag;
	video->dos_setting = arg0.integer.value;
	acpi_evaluate_object(video->handle, "_DOS", &args, NULL);

Failed:
	return_VALUE(status);
}

/*
 *  Arg:	
 *  	device	: video output device (LCD, CRT, ..)
 *
 *  Return Value:
 *  	None
 *
 *  Find out all required AML method defined under the output
 *  device.
 */

static void
acpi_video_device_find_cap (struct acpi_video_device *device)
{
	acpi_integer		status;
	acpi_handle h_dummy1;
	int i;
	union acpi_object *obj = NULL;
	struct acpi_video_device_brightness *br = NULL;

	ACPI_FUNCTION_TRACE("acpi_video_device_find_cap");

	memset( &device->cap, 0, 4);

    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_ADR", &h_dummy1))) {
		device->cap._ADR = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_BCL", &h_dummy1))) {
		device->cap._BCL= 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_BCM", &h_dummy1))) {
		device->cap._BCM= 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DDC", &h_dummy1))) {
		device->cap._DDC= 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DCS", &h_dummy1))) {
		device->cap._DCS = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DGS", &h_dummy1))) {
		device->cap._DGS = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(device->handle, "_DSS", &h_dummy1))) {
		device->cap._DSS = 1;
	}

	status = acpi_video_device_lcd_query_levels(device, &obj);

	if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count >= 2) {
		int count = 0;
		union acpi_object *o;
		
		br = kmalloc(sizeof &br, GFP_KERNEL);
		if (!br) {
			printk(KERN_ERR "can't allocate memory\n");
		} else {
			memset(br, 0, sizeof &br);
			br->levels = kmalloc(obj->package.count * sizeof &br->levels, GFP_KERNEL);
			if (!br->levels)
				goto out;

			for (i = 0; i < obj->package.count; i++) {
				o = (union acpi_object *) &obj->package.elements[i];
				if (o->type != ACPI_TYPE_INTEGER) {
					ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid data\n"));
					continue;
				}
				br->levels[count] = (u32) o->integer.value;
				count++;
			}
out:
			if (count < 2) {
				if (br->levels)
					kfree(br->levels);
				kfree(br);
			} else {
				br->count = count;
				device->brightness = br;
				ACPI_DEBUG_PRINT((ACPI_DB_INFO, "found %d brightness levels\n", count));
			}
		}
	}

	if (obj)
		kfree(obj);

	return_VOID;
}

/*
 *  Arg:	
 *  	device	: video output device (VGA)
 *
 *  Return Value:
 *  	None
 *
 *  Find out all required AML method defined under the video bus device.
 */

static void 
acpi_video_bus_find_cap (struct acpi_video_bus *video)
{
	acpi_handle	h_dummy1;

	memset(&video->cap ,0, 4);
    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_DOS", &h_dummy1))) {
		video->cap._DOS = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_DOD", &h_dummy1))) {
		video->cap._DOD = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_ROM", &h_dummy1))) {
		video->cap._ROM = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_GPD", &h_dummy1))) {
		video->cap._GPD = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_SPD", &h_dummy1))) {
		video->cap._SPD = 1;
	}
    	if( ACPI_SUCCESS(acpi_get_handle(video->handle, "_VPO", &h_dummy1))) {
		video->cap._VPO = 1;
	}
}

/*
 * Check whether the video bus device has required AML method to
 * support the desired features
 */

static int
acpi_video_bus_check (
	struct acpi_video_bus	*video)
{
	acpi_status		status = -ENOENT;


	ACPI_FUNCTION_TRACE("acpi_video_bus_check");

	if (!video)
		return_VALUE(-EINVAL);

	/* Since there is no HID, CID and so on for VGA driver, we have
	 * to check well known required nodes.
	 */

	/* Does this device able to support video switching ? */
	if(video->cap._DOS){
		video->flags.multihead = 1;
		status = 0;
	}

	/* Does this device able to retrieve a retrieve a video ROM ? */
	if(video->cap._ROM){
		video->flags.rom = 1;
		status = 0;
	}

	/* Does this device able to configure which video device to POST ? */
	if(video->cap._GPD && video->cap._SPD && video->cap._VPO){
		video->flags.post = 1;
		status = 0;
	}

	return_VALUE(status);
}

/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

struct proc_dir_entry		*acpi_video_dir;

/* video devices */

static int
acpi_video_device_info_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;

	ACPI_FUNCTION_TRACE("acpi_video_device_info_seq_show");

	if (!dev)
		goto end;

	seq_printf(seq, "device_id:    0x%04x\n", (u32) dev->device_id);
	seq_printf(seq, "type:         ");
	if (dev->flags.crt)
		seq_printf(seq, "CRT\n");
	else if (dev->flags.lcd)
		seq_printf(seq, "LCD\n");
	else if (dev->flags.tvout)
		seq_printf(seq, "TVOUT\n");
	else
		seq_printf(seq, "UNKNOWN\n");

	seq_printf(seq,"known by bios: %s\n",
		   dev->flags.bios ? "yes":"no");

end:
	return_VALUE(0);
}

static int
acpi_video_device_info_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_device_info_seq_show,
			   PDE(inode)->data);
}

static int  
acpi_video_device_state_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	int			status;
	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;
	unsigned long	state;

	ACPI_FUNCTION_TRACE("acpi_video_device_state_seq_show");

	if (!dev)
		goto end;

	status = acpi_video_device_get_state(dev, &state);
	seq_printf(seq, "state:     ");
	if (ACPI_SUCCESS(status))
		seq_printf(seq, "0x%02lx\n", state);
	else
		seq_printf(seq, "<not supported>\n");

	status = acpi_video_device_query(dev, &state);
	seq_printf(seq, "query:     ");
	if (ACPI_SUCCESS(status))
		seq_printf(seq, "0x%02lx\n", state);
	else
		seq_printf(seq, "<not supported>\n");

end:
	return_VALUE(0);
}

static int
acpi_video_device_state_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_device_state_seq_show,
			   PDE(inode)->data);
}

static ssize_t
acpi_video_device_write_state (
	struct file		*file,
	const char		__user *buffer,
	size_t			count,
	loff_t			*data)
{
	int			status;
	struct seq_file		*m = (struct seq_file *) file->private_data;
	struct acpi_video_device	*dev = (struct acpi_video_device *) m->private;
	char			str[12] = {0};
	u32			state = 0;

	ACPI_FUNCTION_TRACE("acpi_video_device_write_state");

	if (!dev || count + 1 > sizeof str)
		return_VALUE(-EINVAL);

	if (copy_from_user(str, buffer, count))
		return_VALUE(-EFAULT);

	str[count] = 0;
	state = simple_strtoul(str, NULL, 0);
	state &= ((1ul<<31) | (1ul<<30) | (1ul<<0));

	status = acpi_video_device_set_state(dev, state);

	if (status)
		return_VALUE(-EFAULT);

	return_VALUE(count);
}

static int
acpi_video_device_brightness_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;
	int			i;

	ACPI_FUNCTION_TRACE("acpi_video_device_brightness_seq_show");

	if (!dev || !dev->brightness) {
		seq_printf(seq, "<not supported>\n");
		return_VALUE(0);
	}

	seq_printf(seq, "levels: ");
	for (i = 0; i < dev->brightness->count; i++)
		seq_printf(seq, " %d", dev->brightness->levels[i]);
	seq_printf(seq, "\ncurrent: %d\n", dev->brightness->curr);

	return_VALUE(0);
}

static int
acpi_video_device_brightness_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_device_brightness_seq_show,
			   PDE(inode)->data);
}

static ssize_t
acpi_video_device_write_brightness (
	struct file		*file,
	const char		__user *buffer,
	size_t			count,
	loff_t			*data)
{
	struct seq_file		*m = (struct seq_file *) file->private_data;
	struct acpi_video_device	*dev = (struct acpi_video_device *) m->private;
	char			str[4] = {0};
	unsigned int		level = 0;
	int			i;

	ACPI_FUNCTION_TRACE("acpi_video_device_write_brightness");

	if (!dev || count + 1 > sizeof str)
		return_VALUE(-EINVAL);

	if (copy_from_user(str, buffer, count))
		return_VALUE(-EFAULT);

	str[count] = 0;
	level = simple_strtoul(str, NULL, 0);
	
	if (level > 100)
		return_VALUE(-EFAULT);

	/* validate though the list of available levels */
	for (i = 0; i < dev->brightness->count; i++)
		if (level == dev->brightness->levels[i]) {
			if (ACPI_SUCCESS(acpi_video_device_lcd_set_level(dev, level)))
				dev->brightness->curr = level;
			break;
		}

	return_VALUE(count);
}

static int
acpi_video_device_EDID_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_device	*dev = (struct acpi_video_device *) seq->private;
	int			status;
	int			i;
	union acpi_object	*edid = NULL;

	ACPI_FUNCTION_TRACE("acpi_video_device_EDID_seq_show");

	if (!dev)
		goto out;

	status = acpi_video_device_EDID (dev, &edid, 128);
	if (ACPI_FAILURE(status)) {
		status = acpi_video_device_EDID (dev, &edid, 256);
	}

	if (ACPI_FAILURE(status)) {
		goto out;
	}

	if (edid && edid->type == ACPI_TYPE_BUFFER) {
		for (i = 0; i < edid->buffer.length; i++)
			seq_putc(seq, edid->buffer.pointer[i]);
	}

out:
	if (!edid)
		seq_printf(seq, "<not supported>\n");
	else
		kfree(edid);

	return_VALUE(0);
}

static int
acpi_video_device_EDID_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_device_EDID_seq_show,
			   PDE(inode)->data);
}


static int
acpi_video_device_add_fs (
	struct acpi_device	*device)
{
	struct proc_dir_entry	*entry = NULL;
	struct acpi_video_device *vid_dev;

	ACPI_FUNCTION_TRACE("acpi_video_device_add_fs");

	if (!device)
		return_VALUE(-ENODEV);

	vid_dev = (struct acpi_video_device *) acpi_driver_data(device);
	if (!vid_dev)
		return_VALUE(-ENODEV);

	if (!acpi_device_dir(device)) {
		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
				vid_dev->video->dir);
		if (!acpi_device_dir(device))
			return_VALUE(-ENODEV);
		acpi_device_dir(device)->owner = THIS_MODULE;
	}

	/* 'info' [R] */
	entry = create_proc_entry("info", S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create 'info' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_device_info_fops;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'state' [R/W] */
	entry = create_proc_entry("state", S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create 'state' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_device_state_fops;
		entry->proc_fops->write = acpi_video_device_write_state;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'brightness' [R/W] */
	entry = create_proc_entry("brightness", S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create 'brightness' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_device_brightness_fops;
		entry->proc_fops->write = acpi_video_device_write_brightness;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'EDID' [R] */
	entry = create_proc_entry("EDID", S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create 'brightness' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_device_EDID_fops;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	return_VALUE(0);
}

static int
acpi_video_device_remove_fs (
	struct acpi_device	*device)
{
	struct acpi_video_device *vid_dev;
	ACPI_FUNCTION_TRACE("acpi_video_device_remove_fs");

	vid_dev = (struct acpi_video_device *) acpi_driver_data(device);
	if (!vid_dev || !vid_dev->video || !vid_dev->video->dir)
		return_VALUE(-ENODEV);

	if (acpi_device_dir(device)) {
		remove_proc_entry("info", acpi_device_dir(device));
		remove_proc_entry("state", acpi_device_dir(device));
		remove_proc_entry("brightness", acpi_device_dir(device));
		remove_proc_entry("EDID", acpi_device_dir(device));
		remove_proc_entry(acpi_device_bid(device),
				 vid_dev->video->dir);
		acpi_device_dir(device) = NULL;
	}

	return_VALUE(0);
}


/* video bus */
static int
acpi_video_bus_info_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;

	ACPI_FUNCTION_TRACE("acpi_video_bus_info_seq_show");

	if (!video)
		goto end;

	seq_printf(seq, "Switching heads:              %s\n",
			video->flags.multihead ? "yes":"no");
	seq_printf(seq, "Video ROM:                    %s\n",
			video->flags.rom ? "yes":"no");
	seq_printf(seq, "Device to be POSTed on boot:  %s\n",
			video->flags.post ? "yes":"no");

end:
	return_VALUE(0);
}

static int
acpi_video_bus_info_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_bus_info_seq_show, PDE(inode)->data);
}

static int
acpi_video_bus_ROM_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;

	ACPI_FUNCTION_TRACE("acpi_video_bus_ROM_seq_show");

	if (!video)
		goto end;

	printk(KERN_INFO PREFIX "Please implement %s\n", __FUNCTION__);
	seq_printf(seq, "<TODO>\n");

end:
	return_VALUE(0);
}

static int
acpi_video_bus_ROM_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_bus_ROM_seq_show, PDE(inode)->data);
}

static int
acpi_video_bus_POST_info_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;
	unsigned long		options;
	int			status;

	ACPI_FUNCTION_TRACE("acpi_video_bus_POST_info_seq_show");

	if (!video)
		goto end;

	status = acpi_video_bus_POST_options(video, &options);
	if (ACPI_SUCCESS(status)) {
		if (!(options & 1)) {
			printk(KERN_WARNING PREFIX "The motherboard VGA device is not listed as a possible POST device.\n");
			printk(KERN_WARNING PREFIX "This indicate a BIOS bug.  Please contact the manufacturer.\n");
		}
		printk("%lx\n", options);
		seq_printf(seq, "can POST: <intgrated video>");
		if (options & 2)
			seq_printf(seq, " <PCI video>");
		if (options & 4)
			seq_printf(seq, " <AGP video>");
		seq_putc(seq, '\n');
	} else
		seq_printf(seq, "<not supported>\n");
end:
	return_VALUE(0);
}

static int
acpi_video_bus_POST_info_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_bus_POST_info_seq_show, PDE(inode)->data);
}

static int
acpi_video_bus_POST_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;
	int			status;
	unsigned long		id;

	ACPI_FUNCTION_TRACE("acpi_video_bus_POST_seq_show");

	if (!video)
		goto end;

	status = acpi_video_bus_get_POST (video, &id);
	if (!ACPI_SUCCESS(status)) {
		seq_printf(seq, "<not supported>\n");
		goto end;
	}
	seq_printf(seq, "device posted is <%s>\n",  device_decode[id & 3]);

end:
	return_VALUE(0);
}

static int
acpi_video_bus_DOS_seq_show (
	struct seq_file		*seq,
	void			*offset)
{
	struct acpi_video_bus	*video = (struct acpi_video_bus *) seq->private;

	ACPI_FUNCTION_TRACE("acpi_video_bus_DOS_seq_show");

	seq_printf(seq, "DOS setting: <%d>\n", video->dos_setting );

	return_VALUE(0);
}

static int
acpi_video_bus_POST_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_bus_POST_seq_show, PDE(inode)->data);
}

static int
acpi_video_bus_DOS_open_fs (
	struct inode		*inode,
	struct file		*file)
{
	return single_open(file, acpi_video_bus_DOS_seq_show, PDE(inode)->data);
}

static ssize_t
acpi_video_bus_write_POST (
	struct file		*file,
	const char		__user *buffer,
	size_t			count,
	loff_t			*data)
{
	int			status;
	struct seq_file		*m = (struct seq_file *) file->private_data;
	struct acpi_video_bus	*video = (struct acpi_video_bus *) m->private;
	char			str[12] = {0};
	unsigned long		opt, options;

	ACPI_FUNCTION_TRACE("acpi_video_bus_write_POST");


	if (!video || count + 1 > sizeof str)
		return_VALUE(-EINVAL);

	status = acpi_video_bus_POST_options(video, &options);
	if (!ACPI_SUCCESS(status))
		return_VALUE(-EINVAL);

	if (copy_from_user(str, buffer, count))
		return_VALUE(-EFAULT);

	str[count] = 0;
	opt = strtoul(str, NULL, 0);
	if (opt > 3)
		return_VALUE(-EFAULT);

	/* just in case an OEM 'forget' the motherboard... */
	options |= 1;

	if (options & (1ul << opt)) {
		status = acpi_video_bus_set_POST (video, opt);
		if (!ACPI_SUCCESS(status))
			return_VALUE(-EFAULT);

	}


	return_VALUE(count);
}

static ssize_t
acpi_video_bus_write_DOS (
	struct file		*file,
	const char		__user *buffer,
	size_t			count,
	loff_t			*data)
{
	int			status;
	struct seq_file		*m = (struct seq_file *) file->private_data;
	struct acpi_video_bus	*video = (struct acpi_video_bus *) m->private;
	char			str[12] = {0};
	unsigned long		opt;

	ACPI_FUNCTION_TRACE("acpi_video_bus_write_DOS");


	if (!video || count + 1 > sizeof str)
		return_VALUE(-EINVAL);

	if (copy_from_user(str, buffer, count))
		return_VALUE(-EFAULT);

	str[count] = 0;
	opt = strtoul(str, NULL, 0);
	if (opt > 7)
		return_VALUE(-EFAULT);

	status = acpi_video_bus_DOS (video, opt & 0x3, (opt & 0x4)>>2);

	if (!ACPI_SUCCESS(status))
		return_VALUE(-EFAULT);

	return_VALUE(count);
}

static int
acpi_video_bus_add_fs (
	struct acpi_device	*device)
{
	struct proc_dir_entry	*entry = NULL;
	struct acpi_video_bus	*video;

	ACPI_FUNCTION_TRACE("acpi_video_bus_add_fs");

	video = (struct acpi_video_bus *) acpi_driver_data(device);

	if (!acpi_device_dir(device)) {
		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
				acpi_video_dir);
		if (!acpi_device_dir(device))
			return_VALUE(-ENODEV);
		video->dir = acpi_device_dir(device);
		acpi_device_dir(device)->owner = THIS_MODULE;
	}

	/* 'info' [R] */
	entry = create_proc_entry("info", S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'info' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_bus_info_fops;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'ROM' [R] */
	entry = create_proc_entry("ROM", S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'ROM' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_bus_ROM_fops;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'POST_info' [R] */
	entry = create_proc_entry("POST_info", S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'POST_info' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_bus_POST_info_fops;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'POST' [R/W] */
	entry = create_proc_entry("POST", S_IFREG|S_IRUGO|S_IRUSR, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'POST' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_bus_POST_fops;
		entry->proc_fops->write = acpi_video_bus_write_POST;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'DOS' [R/W] */
	entry = create_proc_entry("DOS", S_IFREG|S_IRUGO|S_IRUSR, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to create 'DOS' fs entry\n"));
	else {
		entry->proc_fops = &acpi_video_bus_DOS_fops;
		entry->proc_fops->write = acpi_video_bus_write_DOS;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	return_VALUE(0);
}

static int
acpi_video_bus_remove_fs (
	struct acpi_device	*device)
{
	struct acpi_video_bus	*video;

	ACPI_FUNCTION_TRACE("acpi_video_bus_remove_fs");

	video = (struct acpi_video_bus *) acpi_driver_data(device);

	if (acpi_device_dir(device)) {
		remove_proc_entry("info", acpi_device_dir(device));
		remove_proc_entry("ROM", acpi_device_dir(device));
		remove_proc_entry("POST_info", acpi_device_dir(device));
		remove_proc_entry("POST", acpi_device_dir(device));
		remove_proc_entry("DOS", acpi_device_dir(device));
		remove_proc_entry(acpi_device_bid(device),
				acpi_video_dir); 
		acpi_device_dir(device) = NULL;
	}

	return_VALUE(0);
}

/* --------------------------------------------------------------------------
                                 Driver Interface
   -------------------------------------------------------------------------- */

/* device interface */

static int
acpi_video_bus_get_one_device (
	struct acpi_device	*device,
	struct acpi_video_bus	*video)
{
	unsigned long		device_id;
	int			status, result;
	struct acpi_video_device	*data;

	ACPI_FUNCTION_TRACE("acpi_video_bus_get_one_device");

	if (!device || !video)
		return_VALUE(-EINVAL);

	status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
	if (ACPI_SUCCESS(status)) {

		data = kmalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
		if (!data)
			return_VALUE(-ENOMEM);

		memset(data, 0, sizeof(struct acpi_video_device));

		data->handle = device->handle;
		strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
		strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
		acpi_driver_data(device) = data;

		data->device_id = device_id;
		data->video = video;
		data->dev = device;

		switch (device_id & 0xffff) {
		case 0x0100:
			data->flags.crt = 1;
			break;
		case 0x0400:
			data->flags.lcd = 1;
			break;
		case 0x0200:
			data->flags.tvout = 1;
			break;
		default:
			data->flags.unknown = 1;
			break;
		}
		
		acpi_video_device_bind(video, data);
		acpi_video_device_find_cap(data);

		status = acpi_install_notify_handler(data->handle,
			ACPI_DEVICE_NOTIFY, acpi_video_device_notify, data);
		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				"Error installing notify handler\n"));
			result = -ENODEV;
			goto end;
		}

		down(&video->sem);
		list_add_tail(&data->entry, &video->video_device_list);
		up(&video->sem);

		acpi_video_device_add_fs(device);

		return_VALUE(0);
	}

end:
	return_VALUE(-ENOENT);
}

/*
 *  Arg:
 *  	video	: video bus device 
 *
 *  Return:
 *  	none
 *  
 *  Enumerate the video device list of the video bus, 
 *  bind the ids with the corresponding video devices
 *  under the video bus.
 */  

static void
acpi_video_device_rebind( struct acpi_video_bus *video)
{
	struct list_head * node, * next;
	list_for_each_safe(node, next, &video->video_device_list) {
		struct acpi_video_device * dev = container_of(node, struct acpi_video_device, entry);
		acpi_video_device_bind( video, dev);
	}
}

/*
 *  Arg:
 *  	video	: video bus device 
 *  	device	: video output device under the video 
 *  		bus
 *
 *  Return:
 *  	none
 *  
 *  Bind the ids with the corresponding video devices
 *  under the video bus.
 */  

static void
acpi_video_device_bind( struct acpi_video_bus *video,
			struct acpi_video_device *device)
{
	int	i;
	ACPI_FUNCTION_TRACE("acpi_video_device_bind");

#define IDS_VAL(i) video->attached_array[i].value.int_val
#define IDS_BIND(i) video->attached_array[i].bind_info
	
	for (i = 0; IDS_VAL(i) != ACPI_VIDEO_HEAD_INVALID && 
		i < video->attached_count; i++) {
		if (device->device_id == (IDS_VAL(i)& 0xffff)) {
			IDS_BIND(i) = device;
			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
		}
	}
#undef IDS_VAL
#undef IDS_BIND
}

/*
 *  Arg:
 *  	video	: video bus device 
 *
 *  Return:
 *  	< 0	: error
 *  
 *  Call _DOD to enumerate all devices attached to display adapter
 *
 */  

static int acpi_video_device_enumerate(struct acpi_video_bus *video)
{
	int			status;
	int			count;
	int			i;
	struct acpi_video_enumerated_device *active_device_list;
	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object	*dod = NULL;
	union acpi_object	*obj;

	ACPI_FUNCTION_TRACE("acpi_video_device_enumerate");

	status = acpi_evaluate_object(video->handle, "_DOD", NULL, &buffer);
	if (!ACPI_SUCCESS(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _DOD\n"));
		return_VALUE(status);
	}

	dod = (union acpi_object *) buffer.pointer;
	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _DOD data\n"));
		status = -EFAULT;
		goto out;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
		dod->package.count));

	active_device_list= kmalloc(
 		(1+dod->package.count)*sizeof(struct acpi_video_enumerated_device),
	       	GFP_KERNEL);

	if (!active_device_list) {
		status = -ENOMEM;
		goto out;
	}

	count = 0;
	for (i = 0; i < dod->package.count; i++) {
		obj = (union acpi_object *) &dod->package.elements[i];

		if (obj->type != ACPI_TYPE_INTEGER) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _DOD data\n"));
			active_device_list[i].value.int_val = ACPI_VIDEO_HEAD_INVALID;
		}
		active_device_list[i].value.int_val = obj->integer.value;
		active_device_list[i].bind_info = NULL;
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i, (int) obj->integer.value));
		count++;
	}
	active_device_list[count].value.int_val = ACPI_VIDEO_HEAD_END;

	if(video->attached_array)
		kfree(video->attached_array);
	
	video->attached_array = active_device_list;
	video->attached_count = count;
out:
	acpi_os_free(buffer.pointer);
	return_VALUE(status);
}

/*
 *  Arg:
 *  	video	: video bus device 
 *  	event	: Nontify Event
 *
 *  Return:
 *  	< 0	: error
 *  
 *	1. Find out the current active output device.
 *	2. Identify the next output device to switch
 *	3. call _DSS to do actual switch.
 */  

static int 
acpi_video_switch_output(
	struct acpi_video_bus *video, 
	int	event)
{
	struct list_head * node, * next;
	struct acpi_video_device *dev=NULL;
       	struct acpi_video_device *dev_next=NULL;
	struct acpi_video_device *dev_prev=NULL;
	unsigned long state;
	int status = 0;

	ACPI_FUNCTION_TRACE("acpi_video_switch_output");

	list_for_each_safe(node, next, &video->video_device_list) {
		struct acpi_video_device * dev = container_of(node, struct acpi_video_device, entry);
		status = acpi_video_device_get_state(dev, &state);
		if (state & 0x2){
			dev_next = container_of(node->next, struct acpi_video_device, entry);
			dev_prev = container_of(node->prev, struct acpi_video_device, entry);
			goto out;
		}
	}
	dev_next = container_of(node->next, struct acpi_video_device, entry);
	dev_prev = container_of(node->prev, struct acpi_video_device, entry);
out:	
	switch (event) {
	case ACPI_VIDEO_NOTIFY_CYCLE:
	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:
		acpi_video_device_set_state(dev, 0);
		acpi_video_device_set_state(dev_next, 0x80000001);
		break;
	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:
		acpi_video_device_set_state(dev, 0);
		acpi_video_device_set_state(dev_prev, 0x80000001);
	default:
		break;
	}

	return_VALUE(status);
}

static int 
acpi_video_get_next_level(
	struct acpi_video_device *device,
	u32	level_current,
	u32	event)
{
	/*Fix me*/
	return level_current;
}


static void
acpi_video_switch_brightness (
	struct acpi_video_device *device, 
	int	event)
{
	unsigned long level_current, level_next;
	acpi_video_device_lcd_get_level_current(device, &level_current);
	level_next = acpi_video_get_next_level(device, level_current, event);
	acpi_video_device_lcd_set_level(device, level_next);
}

static int
acpi_video_bus_get_devices (
	struct acpi_video_bus	*video,
	struct acpi_device	*device)
{
	int			status = 0;
	struct list_head	*node, *next;

	ACPI_FUNCTION_TRACE("acpi_video_get_devices");

	acpi_video_device_enumerate(video);

	list_for_each_safe(node, next, &device->children) {
		struct acpi_device *dev = list_entry(node, struct acpi_device, node);

		if (!dev)
			continue;

		status = acpi_video_bus_get_one_device(dev, video);
		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Cant attach device\n"));
			continue;
		}

	}
	return_VALUE(status);
}

static int
acpi_video_bus_put_one_device(
	struct acpi_video_device	*device)
{
	struct acpi_video_bus *video;

	ACPI_FUNCTION_TRACE("acpi_video_bus_put_one_device");

	if (!device || !device->video)
		return_VALUE(-ENOENT);

	video = device->video;

	down(&video->sem);
	list_del(&device->entry);
	up(&video->sem);
	acpi_video_device_remove_fs(device->dev);

	return_VALUE(0);
}

static int
acpi_video_bus_put_devices (
	struct acpi_video_bus	*video)
{
	int			status;
	struct list_head	*node, *next;

	ACPI_FUNCTION_TRACE("acpi_video_bus_put_devices");

	list_for_each_safe(node, next, &video->video_device_list) {
		struct acpi_video_device *data = list_entry(node, struct acpi_video_device, entry);
		if (!data)
			continue;

		status = acpi_video_bus_put_one_device(data);
		if(ACPI_FAILURE(status))
			printk(KERN_WARNING PREFIX "hhuuhhuu bug in acpi video driver.\n");

		if (data->brightness)
			kfree(data->brightness);

		kfree(data);
	}

	return_VALUE(0);
}

/* acpi_video interface */

static int
acpi_video_bus_start_devices(
	struct acpi_video_bus	*video)
{
	return acpi_video_bus_DOS(video, 1, 0);
}

static int
acpi_video_bus_stop_devices(
	struct acpi_video_bus	*video)
{
	return acpi_video_bus_DOS(video, 0, 1);
}

static void
acpi_video_bus_notify (
	acpi_handle		handle,
	u32			event,
	void			*data)
{
	struct acpi_video_bus	*video = (struct acpi_video_bus *) data;
	struct acpi_device	*device = NULL;

	ACPI_FUNCTION_TRACE("acpi_video_bus_notify");
	printk("video bus notify\n");

	if (!video)
		return_VOID;

	if (acpi_bus_get_device(handle, &device))
		return_VOID;

	switch (event) {
	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User request that a switch occur,
					 * most likely via hotkey. */
		acpi_bus_generate_event(device, event, 0);
		break;

	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plug or remove a video
					 * connector. */
		acpi_video_device_enumerate(video);
		acpi_video_device_rebind(video);
		acpi_video_switch_output(video, event);
		acpi_bus_generate_event(device, event, 0);
		break;

	case ACPI_VIDEO_NOTIFY_CYCLE: /* Cycle Display output hotkey pressed.*/
	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT: /* Next Display output hotkey pressed. */
	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT: /* previous Display output hotkey pressed. */
		acpi_video_switch_output(video, event);
		acpi_bus_generate_event(device, event, 0);
		break;

	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"Unsupported event [0x%x]\n", event));
		break;
	}

	return_VOID;
}

static void
acpi_video_device_notify (
	acpi_handle		handle,
	u32			event,
	void			*data)
{
	struct acpi_video_device	*video_device = (struct acpi_video_device *) data;
	struct acpi_device	*device = NULL;

	ACPI_FUNCTION_TRACE("acpi_video_device_notify");

	printk("video device notify\n");
	if (!video_device)
		return_VOID;

	if (acpi_bus_get_device(handle, &device))
		return_VOID;

	switch (event) {
	case ACPI_VIDEO_NOTIFY_SWITCH: /* change in status (cycle output device) */
	case ACPI_VIDEO_NOTIFY_PROBE: /* change in status (output device status) */
		acpi_bus_generate_event(device, event, 0);
		break;
	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS: /* Cycle brightness */
	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS: /* Increase brightness */
	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS: /* Decrease brightness */
	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightnesss */
	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF: /* display device off */
		acpi_video_switch_brightness (video_device, event);
		acpi_bus_generate_event(device, event, 0);
		break;
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"Unsupported event [0x%x]\n", event));
		break;
	}
	return_VOID;
}

static int
acpi_video_bus_add (
	struct acpi_device	*device)
{
	int			result = 0;
	acpi_status		status = 0;
	struct acpi_video_bus	*video = NULL;

	ACPI_FUNCTION_TRACE("acpi_video_bus_add");
	
	if (!device)
		return_VALUE(-EINVAL);

	video = kmalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
	if (!video)
		return_VALUE(-ENOMEM);
	memset(video, 0, sizeof(struct acpi_video_bus));

	video->handle = device->handle;
	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
	acpi_driver_data(device) = video;

	acpi_video_bus_find_cap(video);
	result = acpi_video_bus_check(video);
	if (result)
		goto end;

	result = acpi_video_bus_add_fs(device);
	if (result)
		goto end;

	init_MUTEX(&video->sem);
	INIT_LIST_HEAD(&video->video_device_list);

	acpi_video_bus_get_devices(video, device);
	acpi_video_bus_start_devices(video);

	status = acpi_install_notify_handler(video->handle,
		ACPI_DEVICE_NOTIFY, acpi_video_bus_notify, video);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Error installing notify handler\n"));
		result = -ENODEV;
		goto end;
	}

	printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
		ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
		video->flags.multihead ? "yes":"no",
		video->flags.rom ? "yes":"no",
		video->flags.post ? "yes":"no");

end:
	if (result) {
		acpi_video_bus_remove_fs(device);
		kfree(video);
	}

	return_VALUE(result);
}

static int
acpi_video_bus_remove (
	struct acpi_device	*device,
	int			type)
{
	acpi_status		status = 0;
	struct acpi_video_bus	*video = NULL;

	ACPI_FUNCTION_TRACE("acpi_video_bus_remove");

	if (!device || !acpi_driver_data(device))
		return_VALUE(-EINVAL);

	video = (struct acpi_video_bus *) acpi_driver_data(device);

	acpi_video_bus_stop_devices(video);

	status = acpi_remove_notify_handler(video->handle,
		ACPI_DEVICE_NOTIFY, acpi_video_bus_notify);
	if (ACPI_FAILURE(status))
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Error removing notify handler\n"));

	acpi_video_bus_put_devices(video);
	acpi_video_bus_remove_fs(device);

	if (video->attached_array)
		kfree(video->attached_array);
	kfree(video);

	return_VALUE(0);
}


static int
acpi_video_bus_match (
	struct acpi_device	*device,
	struct acpi_driver	*driver)
{
	acpi_handle		h_dummy1;
	acpi_handle		h_dummy2;
	acpi_handle		h_dummy3;

	ACPI_FUNCTION_TRACE("acpi_video_bus_match");

	if (!device || !driver)
		return_VALUE(-EINVAL);

	/* Since there is no HID, CID for ACPI Video drivers, we have
	 * to check well known required nodes for each feature we support.
	 */

	/* Does this device able to support video switching ? */
	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy1)) &&
	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy2)))
		return_VALUE(0);

	/* Does this device able to retrieve a video ROM ? */
	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy1)))
		return_VALUE(0);

	/* Does this device able to configure which video head to be POSTed ? */
	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy1)) &&
	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy2)) &&
	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy3)))
		return_VALUE(0);


	return_VALUE(-ENODEV);
}


static int __init
acpi_video_init (void)
{
	int			result = 0;

	ACPI_FUNCTION_TRACE("acpi_video_init");

	/*
	acpi_dbg_level = 0xFFFFFFFF;
	acpi_dbg_layer = 0x08000000;
	*/

	acpi_video_dir = proc_mkdir(ACPI_VIDEO_CLASS, acpi_root_dir);
	if (!acpi_video_dir)
		return_VALUE(-ENODEV);
	acpi_video_dir->owner = THIS_MODULE;

	result = acpi_bus_register_driver(&acpi_video_bus);
	if (result < 0) {
		remove_proc_entry(ACPI_VIDEO_CLASS, acpi_root_dir);
		return_VALUE(-ENODEV);
	}

	return_VALUE(0);
}

static void __exit
acpi_video_exit (void)
{
	ACPI_FUNCTION_TRACE("acpi_video_exit");

	acpi_bus_unregister_driver(&acpi_video_bus);

	remove_proc_entry(ACPI_VIDEO_CLASS, acpi_root_dir);

	return_VOID;
}

module_init(acpi_video_init);
module_exit(acpi_video_exit);
